Your point is well-taken, but more likely than not the people who haven't heard of the write-in are more likely to be Democrat, because in this CD, the Republicans tend to be middle to upper-middle class and well-educated, with Democrats being mainly black, Hispanic and less educated (the good parts of Missouri City being the exception).
I guess for this reason and a couple of others I'm viewing this as being better for the GOP than you are (though not as good as this forum, obviously): 1/5 of the write-ins in this poll are not sure, they're not voting for someone else; more people know who Sekula-Gibbs is than Lampson, which indicates to me that Lampson might not have a very good GOTV operation.
The negatives are that it's Zogby; secondly, I don't think 60% of people are going to know how to write-in a candidate when only 20% say they've done it before. The smarter ones will be able to figure the system out, but alas, not everyone is smart.
In general, the biggest problem for anyone trying a write-in campaign in Texas is the straight-ticket issue, since so many people use it, especially in urban/suburban areas. The other issues you list are less important in my mind.
Anyway, the number it would probably take for Sekula-Gibbs to win is probably around 75,000. I really can't see Lampson getting more than that in an off-year election, and he might get less.
One other thing, I agree the reporters of the Houston Chronicle are idiots. I was forced to read their crap for years for local news and am now moreso reliant on them since I moved out of the area. For that reason alone, I might agree with you. :)
PS. I looked up the figure and it's even worse than I thought. In 2004 55% of Texas Republicans cast straight party ballots. I had assumed the figure was about 33%. To reiterate for the general lurker public, a straight-party GOP vote will not register anything for the TX-22 House race.